1. Field of the Invention
This invention relates to a louver assembly of the type which is installed in the wall of a building to permit ventilating air from the outside to enter the building. More particularly, this invention relates to a louver assembly which is sight proof, that is, which does not provide a clear line of sight therethrough to ensure the privacy of the occupants of the building, and which substantially prevents rain droplets entrained in air entering the louver from passing therethrough into the building.
2. Description of the Prior Art
U.S. Pat. Nos. 4,064,670 (R. A. Lichtenwald) and 3,287,870 (E. H. Johnson) describe louvers for mounting in the wall of a building or other enclosure to permit ventilating air from the outside to enter such building or enclosure. The louvers of these references include a vertical series of spaced apart blades which are upwardly inclined in the direction of flow and which are supported and retained in position by a generally rectangular frame. In the Lichtenwald reference, and to a lesser extent in the Johnson reference, the configuration of the blades, coupled with the inclination thereof, substantially blocks the flow of rain droplets through the louver and collects and drains the blocked rain. However, a substantially unimpeded, upwardly inclined line of sight exists through a louver of either of these references, and this is frequently objectionable on grounds of the privacy of the occupants of the building, especially when the louver is stationed near ground level, which is frequently the case. Of course, this problem can be partly or largely corrected by increasing the number of blades in a given louver, thereby reducing the spacing between adjacent louvers, but this would add to the original cost of the louver and would increase the air pressure drop across the louver, and both of these effects would be objectionable.
U.S. Pat. No. 3,771,430 (R. W. Lane) describes a drainable blade louver assembly which incorporates blades that are generally in the form of an inverted V. This louver assembly is not disclosed as being sight proof, and it relies heavily on a suspended, protruding extrusion at the outlet of each blade, which is not as effective as the inlet flange and lip of the Lichtenwald reference, to develop its asserted water removal characteristics.